- Exchange Server and Skype for Business support extended on October 14, 2025
- One final ESU will then be available for just six months
- Customers are being urged to upgrade ASAP to stay safe
Microsoft has confirmed a series of welcome updates which will see older versions of its Exchange Server and Skype for Business retain support for a little longer, to give customers time to continue to migrate to newer options.
Exchange Server 2016 and 2019, and Skype for Business 2015 and 2019, will both lose support on October 14, 2025 – the same day that Windows 10 also loses support – but a new Extended Security Update (ESU) will be offered in its place.
Unlike operating system ESUs, Exchange and Skype will only be available with a one-time, six-month ESU program covering critical and important rated security updates, but it’s still a welcome move for those in need of some extra time.
Microsoft offers a six-month ESU on Exchange and Skype
The ESU period will run from October 14, 2025, to April 14, 2026, with no further extensions possible.
Customers can contact Microsoft from August 1 to get pricing and purchase details, as ESUs will not be available via Windows Update or public downloads – just to those who have enrolled in the program.
“This ESU is not an ‘extension of the support lifecycle’,” Microsoft added. “This ESU is a way for customers who might not be able to finalize their migrations to Exchange SE before October 14, 2025.” Redmond made the same comments for Skype in another post.
As such, the company is urging customers to complete migrations to Exchange Subscription Edition (SE) or Skype for Business SE ahead of the end of support.
It’s unclear how many users remain on older, soon-to-be-unsupported versions of Exchange of Skype, but if the Windows 11 migration is anything to go by, it could be a lot. It was only in June 2025 that the number of Windows 10 and Windows 11 installations reached near-parity – before then, the number of people running Windows 10 was far higher.
